1. Field of the Invention
The present invention relates to a technique employed in a glow plug for use in a self-ignition-type internal combustion engine so as to detect combustion pressure of the internal combustion engine.
2. Description of the Related Art
Conventionally, a pressure sensor is provided in a glow plug, which assists in startup of a self-ignition-type internal combustion engine such as a diesel engine, so as to detect combustion pressure of the internal combustion engine (refer to, for example, Patent Document 1). In such a glow plug, a pressure sensor is accommodated within a glow plug main body (housing), which is attached to a cylinder head.
[Patent Document 1] Japanese Patent Application Laid-Open (kokai) No. 2007-120939
3. Problems to be Solved by the Invention
The heater of such a glow plug is exposed to the atmosphere within a combustion chamber. Further; the temperatures of the heater and a pressure detection mechanism increase considerably because of heating by the heater and combustion of fuel within the combustion chamber. However, conventionally, such a considerable temperature increase of the pressure detection mechanism has not been taken into consideration. Therefore, various problems may arise, such as a problem in that a load applied to a pressure sensor changes due to the considerable temperature increase of the pressure detection mechanism.